Preparation of esterlike derivatives of vat dyestuffs



Patented Sept. 3, 1929.-

UNITED STATES PATENT OFFICE.

MARCEL BADER AND CHARLES SUNDEIB,

OFMU'LHOUSE, FRANCE, AND THEODORE VOLTZ, OF BASED, SWITZERLAND, ASSIGNORS TO THE FIRM DURAND & HUGUENIN s.'A., or BASEL, SWITZERLAND.

PREPARATION OF ESTERLIKE DERIVATIVES OF VAT DYESTUFFS.

No Drawing. Application filed July 27, 1923, Serial No. 654,272, and in Germany August 21, 1922.

The U.- S. Patent No. 1,448,251 discloses a process for the manufactureof water-soluble ester-like derivatives of vat-dyestuffs, especially valuable for dyeing and printing purposes, consisting in treating the leuco-compounds of vat-dyestuffs with chlorosulfonic acid in presence of a tertiary base, that is a tertiary organic nitrogen-containing base with or without the use of an indifferent diluent; I

Now we have found that in this process the chlorosulfonic acid can be replaced by salts of this acid, such as the sodium chlorosulfonate. This modification allows of the re-' duction of the quantity to be used on tertiary base, because no free acid is present in the reaction mass which would require a corresponding amount of the tertiary base.

Ewa/ntple.

26 parts of leuco-indigo are introduced, while stirring, at ordinary temperature and with displacement of air by carbondioxide into a mixture of 120 parts of chlorobenzene;

36 parts of dimethylaniline and parts of 86 the solution is allowed to cool down in order to crystallize'out the ester salt. The latter is soluble in water and especially valuable for dyeing and printingpurposes; by means of a suitable oxidizing agent with acid the 40 original dyestufi is reformed.

The body obtained probably corresponds to the formula:

so'x SOeX i 0 0 4:; I wherein! O---O represents hydrogen or metal.

fterwards, an alkali is added and presence of a tertiary organic nitrogen-con- If X stands for sodium, there is a sodium salt which is easily soluble in water.

The herein described modification of the process can be applied in the same sense and to the same extent as in the U. S. patent above referred to.

What we claim, is:

"1. A process for the manufacture of stable esterlike derivatives of vat dyestuffs in solid form soluble in water, consisting in treatmg a leuco compound of a vat dyestufi with a salt of a halogen 'sulfonic acid in presence of a tertiary organic nitrogen-containing base capable of promoting the esterification.

2. A process for the manufacture of stable esterlike derivatives of vat dyestuifs in solid form soluble in water, consisting in treating a leuco compound of a vat dyestuff with a salt of chlorosulfonic acid in presence of a tertiary organic nitrogen-containing base capable of promoting the esterification. 70

3. A process for the manufacture of stable esterlike derivatives of vat dyestufl's in solid form soluble in water, consisting in treating a leuco compound of a vat dyestuif with a salt of chlorosulfonic acid in presence of dimethylaniline.

4. A process for the manufacture of stable esterlike derivatives of vat dyestuffs in solid form soluble in water, consisting in treating the leuco compound of indigo with a salt of a halogen sulfonic acid in presence of a tertiary organic nitrogen-containing base capable of promoting the esterification. 1

5. A process for the manufacture of stable esterlike derivatives of vat dyestuffs in solid form soluble in water, consisting in treating a leuco'compound of a vat dyestufi with an alkali salt of a halogen sulfonic acidin taining base capable of promoting the esterification; V

6. A process for the manufacture of stable esterlike derivatives of vat dyestuifs in solid form soluble in water, consisting in treating the leuco compound of indigo with a salt of chlorosulfonic acid in resence of a tertiary organic nitrogen contaming base capable of promoting theresterification.

7. A process for the manufacture of stable in the leuco compound of indigo with an 19 esterlike derivatives of vat dyestuffs in solid al ali salt of chlorosulfonic acid in presence form soluble in water, consisting in treatof dimethylaniline. ing the leuco compound of indigo with a salt In witness whereof we have hereunto 5 of chlorosulfonic acid in presence of disigned our names this 12th day of July 1923.

methfianmne' 'MARGEL BADER 8. process or the manufacture of stable esterlike derivatives of vat dyestufis in solid CHARLES SUNDER- form soluble in water, consisting in treat- THEODORE VOLTZ. 

